Dynamo-electric machine.



A. s. HUBBARD.

DYNAMO ELECTRIC MACHINE. APPLICATION FILED JULY 3, 1908.

970,827. Patented Sept.20,1910.

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A. S. HUBBARD. DYNAMO ELECTRIC MAGHINE.

I APPLICATION FILED JULY 3, 1908. 970,827. Patented Sept. 20, 1910.

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970,827. l Patented Sept 20,1910.

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STATES PATENT OFFICE.

ALBERT S. HUBBARD, OF BELLEVILLE, NEW JERSEY, ASSIGNOR T0 GOULD STORAGEBATTERY COMPANY, A CORPORATION OF NEW YORK.

DYNAMO-ELECTRIC MACHINE.

Specification of Letters Patent.

Application filed July 3, 1908.

Patented Sept. 20, 1910. Serial No. 441,739.

T 0 all whom it may concern:

Be it known that I, ALBERT S. HUBBARD, a citizen of the United States,and a resident of Belleville, county of Essex, and State of New Jersey,have invented certain new and useful Improvements in Dynamo-ElectricMachines, of which the following is a specification.

In this application I describe and claim subject matter which wasdisclosed in my prior application, Serial No. 421,932, filed March 18th,1908, for improvements in electrical systems of distribution.

The present invention relates to dynamoelectric machines and moreespecially to those with a uniform field or of the unipolar type and foroperation with alternating or undulating currents.

Generally speaking it is the object of my invention to provide analternating current machine which will operate both as a motor orgenerator without sparking; which will run equally well on currents ofvery high frequencies and currents of very low frequencies: and, thefrequency of which is in no way dependent on the speed. With such amachine it is possible to produce alternating currents of a much lowerfrequency than with other machines and there is no danger of its fallingout of synchronism withvariations in speed or load. The fact thatextremely low frequency currents can be readily and satisfactorilyproduced by such a machine makes it especially adaptable as a telephonerepeater, in which it is desired to take the feeble undulating currentand produce, in synchronism therewith, a relatively much strongercurrent but having ex actly the same wave form and undulations.

Further and more specific objects and features of my invention willclearly appear from the detailed description given below taken inconnection with the accompanying drawing which forms a part of thisspecification.

In the drawing, Figure 1 is a vertical longitudinal sectional view of myimproved dynamo-electric machine taken substantially on the line II ofFig. 2. Fig. 2 is a vertical sectional View of the same taken on theline II-II of Fig. 1. Fig. 3 is a detail View showing the constructionof the brush slots 7.

cular side plates (5 are apertures 8 for the 'which engage 011 theoutside of flanges 5, 5,

on the circular side plates 6, 6. The circular side plates, forming partof the frame, are provided with a plurality of long narrow Through thecenter of these ciraxle of the armature of the machine. The slots 7 aremade radial and in planes parallel to or in the same plane with saidaxle. lVithin the slots' 7 I arrange a plurality of thin plates orlaminations, 9, having a U-shaped form. The legs, 10, of these variouslaminations extend inwardly beyond the slots 7 and come into closeproximity to each other, so as to form a unipolar field structure. Theplates or laminations 9 are held firmly by the slots, 7, in planesparallel with the armature shaft and radial to it. Between the legs, 10,of the laminations I arrange a field coil 11 which is circular in formand concentric with the axis of the ma chine or the axle of thearmature. This field coil 11 is supplied or energized by alternating orundulating currents and for this purpose the leads 12 are provided.

In Fig. 5, I have shown the leads 12 connected to the secondary 30 of atransformer 31, the primary 32 of which is connected in series in acircuit 33 fed by a single phase alternator 34. The condenser 36 isincluded to regulate for phase relation.

The circular side plates 6 are provided with bearings 13 for the shaft14 of the armature 15. The armature 15 consists in this particularinstance of a flat disk or plate, of magnetic material such as steel,circular in form, and extends between the legs, 10, of the Ushapedlaminations 9 and is adapted to be rotated therebetween. Oil wells 16are provided in the bearings 13, and on the outer end of shaft 14 Iprovide a and its center.

pulley 17 for rotating the armature 15; or the armature 15 may bedirectly connected to a inotor 35 as shown in Fig. 5.

18 represents a brush bearing upon the outer edge of the armature disk15, (see Figs. 1 and 3). The brush 18 is connected to a short shaft 19which extends through one of the side plates 6 and has an arm 20 on itsouter end, (see also Fig. 4). The shaft 19 is rotatably mounted in abushing 21 which is insulated from the side plate 6 by a rubber or micabushing 22. At the lower end of the arm 20 I secure one end of a spiralspring 23, the other end of said spring 23 being fastened to a pin 24and insulated therefrom by a suitable covering 25, (see Fig. 4). Thespring 23 always maintains the brush 18 in proper contact with thearmature disk 15. The current is taken from the armature by means ofbrush 18, arm 20, and lead 26, at one point. The other terminal of thearmature may be any part of the frame of the machine, or a brush 28hearing on shaft 14 and secured to an upright post 27 and lead 29, asshown in Fig. 3 may be used for this purpose.

IVhen in operation the coil 11 is energized by alternating or undulatingcurrents and produces an alternating or undulating flux in the fieldstructure embracing the laminations 9. This flux passes from the legs 10through the disk 15 and sets up a difierence of potential thereinbetween its periphery WVhen these points are connected to an externalcircuit as by the frame of the machine and brush 18 through leads 27 and29 this difference of potential will set up a current which has the samefrequency and wave form as the exciting current in coil 11 and thisfrequency will not be affected by any speed changes or variations of thearmature. Since at no time is a material difference of potential createdbetween the brush 18 and the nearby parts of the periphery of the disk15 all sparking at the brushes is effectively eliminated. This is truewhether the armature disk 15 be rotated in one direction or the other.There is no danger of the machine falling out of synchronism since thefrequency and phase are dependent alone upon the frequency and phase ofthe exciting current. When used as a telephone repeater, the feebletelphone current. may be dissipated in the field coil 11 and a muchstronger current delivered to the leads 27 and 29. The latter currentwill, however, have the same wave form and all the undulations of theoriginal telephone current. The increased energy produced in theexternal circuit is derived from the mechanical source of power whichdrives the armature.

It is evident that such a machine has a very low internal resistance andthe radial laminations of the field structure substantially eliminateeddy current losses and ma= terially cut down the distortion due to selfinduction.

Many minor details and changes may be made in the above apparatuswithout departing from the spirit or scope of my invention, but

hat I claim as new anddesire to secure by Letters Patent is:

1. In a field structure for dynamo-electric machines, a plurality ofradially arranged laminations having their inner ends in close proximityto each other, so as to form a unipolar field structure.

2. In a field structure for dynamo-electric machines, a plurality ofradially arranged laminations having their inner ends in close proximityto each other forming a substantially continuous ring of laminatedmagnetic material and a magnetizing coil concentric with said ring.

3. In a field structure for dynamo-electric machines, a plurality ofradially arranged laminations having their inner ends in close proximityto each other so as to form a unipolar field structure and a magnetizingcoil adapted to be connected to a source of alternating current.

4. In an alternating current dynamo-electric machine, a homopolar fieldstructure formed of radial laminations, a field coil partially embracedby said laminations and adapted to be energized by alternating currentsand a rotatable metallic armature within said field coil.

5. In-a dynamo-electric machine, a field structure embracing radiallaminations substantially U-shaped and a field coil located between thelegs of the U-shaped laminations.

6. In a dynamo-electric machine, a field structure embracing radiallaminations substantially U-shaped and lying in planes substantiallyparallel with the armature shaft, a field coil arranged between the legsof said Ushaped laminations and an armature arranged to rotate betweensaid legs.

7. In a dynamo-electric machine, a field structure formed of U-shapedlaminations, a field coil adapted to be excited by alternating currentslocated between the legs of said U-shaped laminations, an armature ofmagnetic material, means for taking 01f the current generated in saidarmature and means for rotating said armature between the legs of saidU-shaped laminations.

8. In a dynamo-electric machine, a frame provided with a plurality ofslots, a plurality of thin plates of magnetic material arranged in saidslots, means for magnetically energizing said plates, and an armature.

9. In a dynamo-electric machine, a frame provided with a plurality ofradial slots, a plurality of plates of magnetic material arranged insaid slots in planes substantially parallel with the shaft a coiladapted to be energized by alternating currents for magneticallyenergizing said plates, and a rotatable armature.

10. In a dynamo-electric machine, a frame embracing two side plates eachprovided with a plurality of radial slots, a plurality of thin plateseach of which engages wit-h one of the slots of both of said firstmentioned plates, a field coil for energizing said plates magneticallyand an arniaturc.

11. In a dynamo electric machine, a frame provided with a plurality ofslots, a plurality of thin plates of magnetic material arranged in saidslots and means for magnetically energizing said plates.

12. In a dynamo electric machine a field structure formed of magneticmaterial and U-shaped in cross-section in planes substantially parallelwith the shaft, said structure bein laminated, a coil adapted to beexcited by alternating currents located between the legs of saidU-shaped structure, an armature of magnetic material, means for takingoff the current generated in said armature and means for rotating saidarmature between the legs of said U-shaped structure.

In testimony whereof, I have signed my name to this specification, inthe presence of two subscribing witnesses.

ALBERT S. HUBBARD.

lVitnesses GORHAM CROSBY, EDWIN SEGER.

